I have hauled groceries for years , but the stuff does not stay on the bike for much more than an Hour at a Time.

Tubus Racks I got 1 set of 10mm only type 1 hooks, and transferred another set from an older Sport-packer pair To the Front Rollers,

I used the Newer hooks for its smaller insert option on my Bike Friday Front rack that is smaller than 8mm Tubing..


You could do actual Testing , know where you can borrow a Gallon Paint can Shaker for the test?